That's exactly what they're saying.
AAM implementation isn't a technical issue, its a legal issue. Seagate is involved in a patent infringement lawsuit with MIT and Convolve, over algorithms used in their AAM firmware.
(Those with a love of math will be excited about the fact that the patent in question involves the use of partial fraction expansion equations!
)
That Seagate response sounds like a tongue-in-cheek explanation of how they are skating around the injunction. They can't use the patent's information, but there's nothing stopping them from making the drives themselves capable of doing so, with the help of an independent (and thus independently legally liable) third party. It's the same principle behind the fact that you can't sue your car company for making a car that goes fast enough to get you a speeding ticket.
What struck me funniest was the comparison between the response that Cactus got:
Seagate has decided that we will no longer support AAM. Our drives are extremely quiet while operating at the highest performance levels, so we believe the ability to switch between Modes is unnecessary. If you want a utility that will switch AAM modes you must procure it from a third party. Seagate cannot make any recommendations as to what third party utility you choose to use, nor do we in any way support the utilities. However you can perform an Internet search for Automatic Acoustic Management and select from the available 3rd party.
...and the language in the original Seagate press release a couple of years ago about why they were dropping AAM support:
Seagate has decided that we will no longer support AAM. Seagate is in the process of removing all product information pertaining to the support of AAM. Our drives are extremely quiet while operating at the highest performance levels, so we believe the ability to switch between Modes is unnecessary. We are also involved in patent litigation with Convolve and MIT. Although we believe the lawsuit is without merit, Convolve alleges that one of its patents, US Patent No. 6,314,473, covers AAM technology
Perhaps Seagate is hedging their bets that during the lifespan of the 7200.8 models the lawsuit will be settled. Maybe they know something we don't.
hooray for legal loopholes. 
